Jacketing internal-combustion engines



April 20, 1926.

W. MAUSS JACKETING INTERNAL COMBUSTION ENGINES Filed Oct. 23, 1924 If Patented Apr. 20, 1926.

; PATENT OFFICE.

hWILHELM MAUSS, or DULRBAN, NATAL, SOUTH AFRICA.

JACKETING INTERNAL-COMBUSTION ENGINES.

Application filed October 23, 1924. Serial No. 745,476.

To all whom it may concern:

Be it known that I, WILH.ELM MAUSS, a British subject, residing at Durban, Natal Province, Union of South Africa, have invented certain new and useful Improvements in J acketing Internal-Combustion Engines, of which the following is a specification. I

In an internal combustion engine the thickness of the liner forming the wall between the cylinder chamber containing the working gas and the jacket chamber containing the cooling liquid has to be determined with due regard to two conflicting considerations. On the one hand the liner must be thick enough to withstand the internal bursting pressure of the working gas. On the other hand it must be thin enough to conduct heat sufficiently rapidly to main-' tain its internal surface at a safe temperature. Since increase in the diameter of the cylinder necessitates a corresponding increase of the thickness inorder to maintain the mechanical strength, the necessity for adequate heat conduction has imposed an undesirable limitation of the cylinder diameters of Diesel and like engines which operate under conditions of high temperature and pressure.

According to the present invention, the fluid in the jacket is maintained always at substantially the pressure of the working gas within the cylinder, so relieving the liner of substantially all bursting stress and enabling it to be made thin enough to transmit heat without difficulty. he outer wall of the jacket, having no cooling function to perform, can be made as thick as is necessary for mechanical strength. The invention is illustrated panying drawings in which:

Fig. I is a vertical section of a Diesel engine embodying the invention.

Fig. II is a horizontal section on II Fig. I.

in the accom- Fig. III is similar to Fig. I but shows a modified form of the invention. I

Fig. IV is an enlarged view of part of Fig. III.

2 indicates the piston of the engine, 3 the piston rod, 4 the connecting rod and 5 the crank. The cylinder comprises an outer wall 6 and a liner 7 within which the piston works, the chamber 8 between the .wall .6 and the liner 7 containing the jacketing Water. I

In the arrangement illustrated in Figs. I and. II, direct communication is made between the upper end of the cylinder chamber 9 and the jacket chamber 8. The upper end of the jacket fits, in the usualmanher, into an annular slot 10 in the cover 11;

and the direct communication is made by cutting a number of small channels 12 in the sides of said slot. sures on both sides of the liner 7 above the piston are always substantially equalized, enabling the liner to be made thin enough to transmit heat readily.

When the piston is at its upper position, pressure is transmitted throughout the jacket chamber without there being a corresponding internal'pressure on the portion of the liner below the piston. Accordingly the liner is thickened at its lower end to withstand this'unbalanced external pressure. Ashowever temperatures towards the lower end of the cylinder are relatively low, this thickening of the jacket does not prevent the necessary heat transfer at its lower end.

The jacket water may be cooled either by circulating it through an external cooler, or by causing it to evaporate, or by a combination of both of these methods.

For external cooling there is provided a circulating system which is preferably made of. piping in order to withstand the high pressure to which the jacket liquid is subjected. As shown, it consists of an inlet pipe 13 to the lower end of'the jacket, an outlet pipe 14 from the upper end of the jacket, cooling coils '15, and a circulating volume of water in the system and which preferably makes its feeding stroke when the pressure in the engine cylinder is high. As

, air in the system would be alternately compressed and expanded, so tending to eject water from the system, it is evacuated from the cook 17, which may be left slightly open for this purpose andalso for passin off surplus water fed into the system by t e make- By this meansthe presup pump 18. The cooler 15 would be so designed and operated as to maintain the water below the boiling point at atmospheric pressure.

If it is desired to effect cooling by evaporation, the circulating pump 16, the cooling coils 15, and the outlet pipe 14: are omitted; the make-up pump 18 with its inlet pipe 13, and the air cock 17 being retained. The method of operation then is that at the end of the compression stroke and the beginning of the working stroke of the piston 3 the j acketing water becomes heated above its boiling point at atmospheric pressure. As

the piston, 2 descends and the pressure within the cylinder and the jacket falls, steam is generated in the jacket, taking its latent heat of evaporation from the remainder of the jacket Water and so cooling the same. The steam expands into the engine cylinder and assists the working stroke. The make-up pump 18 is accelerated or enlarged to supply the increased quantity of water consumed in this method of working.

In practice, both the external cooling and the evaporation methods may be used together, the one supplementing the other. Thatis to say the circulating pump 16 may be run at reduced speed, insufficient to mamtain the water always below the temperature of boiling at atmospheric pressure, the consequent. boiling of the water when the pressure. falls automatically absorbing the surplus heat unabsorbed by the cooler.

Fig. III illustrates an arrangement in which equality of pressure between the working fluid and jacket liquid is maintained without there being actual communication between them. For this purpose there 1s interposed between the two fluids a yielding member such as the piston 19 floating freely in the cylinder 20, the ends of which communicate respectively with the jacket and the cylinder chamber.

This arrangement operates with the external cooler 15 and the circulating pump 16; the production of steam in the jacket being avoided. ater to make up any loss from the jacket and circulatory system is supplied automatically from a reservoir 21,

which communicates with the water system through a non-return valve 22. The reservoir 21 places the water at the valve 22 under a pressure head slightly greater than the lowest normal Working pressure in the engine cylinder. At each exhaust stroke of the engine this pressure drives the piston 19 to the top of its stroke, additional water automatically feeding in in case the water system is incompletely filled.

In order toavoid any danger of the proper pressure not being maintained in the jacket due to lack of water, slots 23 are formed in the upper end of the piston, which co-operate With the openings 24 in the lower end of the cylinder 20 to provide direct communication between the cylinder chamber 9 and the jacket chamber 8 in case the piston 9 reaches the lower limit of its travel.

Owing to the slight yielding of the water and the parts in which it is enclosed, the piston moves back and forth during the working stroke of the engine. A pointer 25 attached to the piston 19 shows this movement and indicates to the attendant whether the piston is maintaining the. position, proper to it when the system is completely filled with water.

I claim:

1'. The method which consists in maintaining substantial equality of pressure between the working fluid in the cylinder of an. internal combustion engine and the liquid j acketing such cylinder.

2. The method which consists in circulate ing the jacketing liquid of an internal combustion engine through a closed circuit which is so connected to. the cylinder charm. her that substantial equality of pressure is maintained in said chamber and said circuit, cooling the liquid externally of the jacket and making up liquid lost from the circuit.

3. The method which consists in maintains.

ing substantially equal pressure between the working fluid of an internal combustion engine and the liquid j acketing the cylinder of the engine whilst maintaining such fluids separate from one another, circulating the.

liquid and cooling the same externally of the jacket and supplying fresh liquid to the. system at a pressure slightly greater than the normal low working pressure of they working fluid.

l. The combination with the cylinder of an internal combustion engine, of a jacket chamber and means to maintain, equal pressure between the working fluid in the cylinder and the liquid in the ack-et.

5. The combination with. the cylinder of an internal combustion engine, of a jacket chamber, means to maintain substantially equal pressure between the working fluid in the cylinder and the liquid in the jacket, means to circulate the jacket liquid including a cooler external of the jacket and means to supply make-up liquid under pressure to the jacket system.

6. The combination with the. cylinder of an internal combustion engine, of a. jacket chamber, and a yielding member separating the cylinder fromv the chamber whilst allowing the transmission of pressure from one to the other.

7. The combination with, the cylinder of an internal combustion engine, of a jacket chamber, a yielding member separating the cylinder from the chamber and movable to transmit pressure from one tothe other, and means providing direct communication be.- tween the cylinder and the jacket chamber,

such means being normally closed by the yielding member and being opened by full movement of the yielding member towards the jacket chamber.

8. The combination With the cylinder of an internal combustion engine, of a jacket chamber, a yielding member separating the cylinder from the chamber Whilst allowing the transmission of pressure from one to the other, means to supply liquid to the jacket 10 system under a pressure head greater than the low *Working slightly ressure in system.

In testimony whereof I have hereunto set my hand.

WILHELM MAUSS. 

